Xyrem (sodium oxybate)

Reviewed by: HU Medical Review Board | Last reviewed: March 2023 | Last updated: April 2023

Xyrem® (sodium oxybate) is a depressant (sedative) of the central nervous system (CNS). It treats daytime sleepiness and cataplexy in people with narcolepsy. Xyrem is approved to be prescribed to people ages 7 and older.1

How does Xyrem work?

Xyrem is a CNS depressant. Its active ingredient is sodium oxybate. Xyrem works especially well to control severe cataplexy. Some improvements may be seen in the first few days. However, it can take 3 months or longer before it fully helps with symptoms.1,2

There are complex mechanisms involved in how Xyrem works to treat cataplexy. It is believed that it helps with daytime sleepiness by improving the quality of nighttime sleep.2

What are the possible side effects of Xyrem?

Xyrem has many possible side effects. The most common side effects are:2-4

  • Morning sleepiness
  • Nausea, vomiting, diarrhea, stomach pain
  • Dizziness
  • Loss of bladder control (bedwetting)
  • Headache
  • Back pain
  • Weakness
  • Swelling of the arms, hands, feet, ankles, or lower legs
  • Sweating
  • Tremors

Serious side effects should be reported to a doctor right away and include:2-4

  • Confusion at night or while awake
  • Sleepwalking
  • Agitation, anxiety, depression, paranoia, aggression
  • Changes in weight or appetite
  • Suicidal thoughts
  • Hallucinations
  • Psychosis
  • Seizures
  • Weak or shallow breathing, breathing that stops
  • Coma

Xyrem has a boxed warning, the strictest warning from the US Food and Drug Administration (FDA). It has this warning because:1

  • It may slow the CNS too much, causing life-threatening breathing problems.
  • It has a high risk of misuse or abuse and is extremely dangerous when used with other CNS depressants.

These are not all the possible side effects of Xyrem. Talk to your doctor about what to expect when taking Xyrem. You also should call your doctor if you have any changes that concern you when taking Xyrem.

Other things to know

Xyrem is also known as gamma hydroxybutyrate, or GHB. Because of its potential for abuse and misuse, the FDA tightly controls its use, and it comes with serious warnings.4,5

Xyrem may be habit-forming. This means the person taking it may:4

  • Develop cravings for the drug
  • Want to take larger and larger doses
  • Take the drug despite unpleasant side effects

Stopping Xyrem suddenly may create withdrawal symptoms. It is better to gradually take less Xyrem over time, with the guidance of your doctor.4

Your doctor must be registered in a special program to be able to prescribe Xyrem. Then, you will only be able to get the drug from a certified pharmacy that is also part of the program. The program is called Risk Evaluation and Mitigation Strategies and is run by the FDA.1,5

Before beginning treatment for narcolepsy, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.

For more information, read the full prescribing information of Xyrem.

Other treatments for narcolepsy

In addition to Xyrem, other drugs that are used to treat narcolepsy include wake-promoting drugs and antidepressants. Your doctor will decide which treatments are best for you based on your symptoms and how you respond to different drugs.2

People being treated for narcolepsy should see their doctor once or twice a year. If your medicines are being adjusted, you should see your doctor more often. All of the drugs taken for narcolepsy can interact with many other medicines. It is important to watch for drug side effects, changes in sleep or mood, and other health issues.1

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